#define NUM_EXTRUDER 1

With #define DUAL_X_AXIS 0 the printer works perfectly with one X-Carriage (X1 motor).

#define BLUETOOTH_SERIAL 1

#define CONFIGURATION_H

#define SD_EXTENDED_DIR 1 /** Show extended directory including file length. Don't use this with Pronterface! */

#define BLUETOOTH_SERIAL 1

#define Z_PROBE_RUN_AFTER_EVERY_PROBE ""

#define DUAL_X_AXIS 1

#define ZHOME_HEAT_HEIGHT 20

#define FEATURE_DITTO_PRINTING 1

#define CONFIGURATION_H

#define EXT0_X_OFFSET 0

#define EXT1_X_OFFSET 32640   // 408 mm * 80 step/mm  

#define HOMING_ORDER HOME_ORDER_ZXY

#define Z_PROBE_SWITCHING_DISTANCE 0

#define Z_PROBE_RUN_AFTER_EVERY_PROBE ""

#define Z_PROBE_SWITCHING_DISTANCE 0

#define Z_PROBE_PIN ORIG_Y_MIN_PIN

#define MOTHERBOARD 402

#define EXTERNALSERIAL